Amazon.com Inc snapped up live-streaming gaming network Twitch Interactive for about $970 million in cash, as the company is trying to transform into an Internet destination beyond its core retail operations.

Twitch's format, which lets viewers message players and each other during live play, is garnering interest as one of the fastest-growing segments of digital video streaming, which in turn is attracting more and more advertising dollars.

The deal, expected to close in the second half of the year, is an unusual step for Amazon, which tends to build from within or make smaller acquisitions.

"Broadcasting and watching gameplay is a global phenomenon and Twitch has built a platform that brings together tens of millions of people who watch billions of minutes of games each month – from The International, to breaking the world record for Mario, to gaming conferences like E3. And, amazingly, Twitch is only three years old," said Jeff Bezos, founder and CEO of Amazon.com. "Like Twitch, we obsess over customers and like to think differently, and we look forward to learning from them and helping them move even faster to build new services for the gaming community."

"Amazon and Twitch optimize for our customers first and are both believers in the future of gaming," said Twitch CEO Emmett Shear. "Being part of Amazon will let us do even more for our community. We will be able to create tools and services faster than we could have independently. This change will mean great things for our community, and will let us bring Twitch to even more people around the world."